Can polylactic acid be a CAD/CAM material for provisional crown restorations in terms of fit and fracture strength?

This study aimed to evaluate polylactic acid (PLA) as a provisional crown material. Lower right first molar phantom tooth was used for the fabrication of 60 crowns. Samples were divided into three groups (n=20) according to the material: Group PL (PLA), Group PM (polymethyl methacrylate), and Group PE (polyetheretherketone).

Thermal, structural and morphological characterization of dental polymers for clinical applications.

Purpose: Polymers are used in dentistry on a daily basis due to their mechanical, functional and aesthetic properties. However, such biomaterials are subject to deterioration in the oral environment. Thus, this study aimed to evaluate the structural properties of five commonly used dental polymers to determine their best clinical indications.

Effects of molecular weight and crystallizability of polylactide on the cellulose nanocrystal dispersion quality in their nanocomposites.

This study investigated how cellulose nanocrystals (CNC) dispersion quality and its percolation network formation could be influenced when using polylactide (PLA) with various molecular weights and crystallizability. In this context, systematic rheological experiments were conducted on PLA/CNC nanocomposites prepared through solution casting method using dimethylformamide (DMF) as the solvent. It was found that lower CNC percolation concentrations could be obtained when a PLA matrix possesses lower molecular weight as the shorter chains and CNCs interpenetration could be facilitated during their dissolution in the solvent.

Surface characterization and bonding properties of milled polyetheretherketone dental posts.

PEEK has been used in many dental applications except intra-radicular post. The aim of this study is to test polyetheretherketone (PEEK) as a dental post material through tensile bond strength (TBS) and surface roughness (SR), and to compare it with glass-fiber and cast-metal posts. Thus, 60 human maxillary central incisors with a single root were endodontically treated and divided into three groups (n = 20) according to the type of post (Group P: PEEK, Group F: Glass-fiber, Group M: Cast-metal).

Surface roughness and wear behavior of occlusal splint materials made of contemporary and high-performance polymers.

With the development of a digital technology of computer-assisted manufacturing (CAD/CAM) and new age materials, the use of new types of occlusal splint is to consider. The aim of the present study was to evaluate the surface roughness (Ra) and wear behavior of different CAD/CAM materials against enamel antagonist through a simulated chewing test. A total of 75 specimens made from ethylene vinyl acetate (EVA), polymethyl methacrylate (PMMA), polycarbonate (PC), polyetheretherketone (PEEK), and polyethyleneterephthalate (PETG) as a control were polished to evaluate the Ra before loading by optical profilometry and further analyzed by scanning electron microscopy (SEM).

Micro-UFO (Untethered Floating Object): A Highly Accurate Microrobot Manipulation Technique.

A new microrobot manipulation technique with high precision (nano level) positional accuracy to move in a liquid environment with diamagnetic levitation is presented. Untethered manipulation of microrobots by means of externally applied magnetic forces has been emerging as a promising field of research, particularly due to its potential for medical and biological applications. The purpose of the presented method is to eliminate friction force between the surface of the substrate and microrobot.